碩士 / 國立屏東科技大學 / 水產養殖系所 / 106 / This study examined the mechanisms of action of Bacillus subtilis E20 in activating the immunity of shrimp via dietary administration. The white shrimp were firstly divided into two groups, one group was fed a control diet (a basal diet) and the other fed an E20-containing diet (a basal diet with 109 CFU kg-1 of B. subtilis E20 added). After the 8-week feeding regimen, the composition of hepatopancreas metabolite in shrimp were investiagted using 1H nuclear magnetic resonance (1H NMR) based metabolomic analysis. Results from the 1H NMR analysis revealed that 18 hepatopancreatic metabolites were matched and identified among treatments, of which 4 metabolites were significantly different (p<0.05). In addition, after performing the reverse-phase high-performance liquid chromatography (RP-HPLC) and spectrophotometric analyses, 4 metabolites have been confirmed including hypoxanthine, 3-methylxanthine, creatinine, and glutamine. On the other hand, results from transcriptome analysis indicated a significant increases in immune-related gene expressions in the hepatopancreas of E20-fed shrimp, including superoxidase dismutase (SOD), mitogen-activated protein kinase (MAPK), MAPK kinase 7, lysozyme, and heat shock protein 70 (HSP70). Interestingly, the real-time ploymerase chain reaction (Q-PCR) were also employed to find that glycosylation pathway-related genes, that are able to bind glutamine, in the E20 group increased significantly as compared with the control (p<0.05), including glutamine fructose-6-phosphate aminotransferase (GFPT) for transfer of amino groups on the substrate, and UDP-N-acetylglucosamine-peptide N-acetylglucosaminyl transferase. Both 1H NMR metabolomic-based and next generation sequencing (NGS) analyses demonstrated that increased glutamate in the hepatopancreas may lead to increase of the glycosylation of foodstuff, resulting in increased the rate of protein glycosylation in shrimp. Results from Q-PCR analysis also substantiated that mRNA expression of HSP70 in hepatopancreas of E20-fed shrimp was significantly higher than that of the control (p<0.05). Moreover, the digestibility experiments were conducted, showing that E20-fed shrimp used all glutaric acid then siginicantly converted into glutamate in hepatopancrease. In conclusion, B. subtilis E20 may increase the absorption of glutamine, thereby promoted the process of glycosylation, resulting in increase of the content of glycosylated HSP70 in the hepatopancreas, and then activating white shrimp immunity.
| Identifer | oai:union.ndltd.org:TW/106NPUS5086003 |
| Date | January 2018 |
| Creators | Chi, Chia-Chun, 紀佳君 |
| Contributors | Liu, Chun-Hung, 劉俊宏 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 79 |
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